Electronic devices are often used in wellbore applications for activating downhole devices, such as detonators, valves, packers, and so forth. Examples of electronic devices include diodes and switches. A popular type of electronic device is the semiconductor electronic device, such as a semiconductor diode or a semiconductor transistor that forms a switch.
A shortcoming of semiconductor electronic devices is that they exhibit reduced reliability in a high temperature environment, such as in a wellbore. The leakage current of a semiconductor diode increases exponentially with temperature. Reliable operation may thus not be achievable when using such semiconductor diodes at high temperatures, particularly if the semiconductor diodes are left in the high temperature wellbore environment for long periods of time (e.g., many days). Switches implemented with semiconductor devices also exhibit reduced reliability at high temperature.
High-voltage operation of tools is often employed for wellbores. For example, high voltages are used to fire detonators associated with perforating guns. Activating voltages for detonators of perforating guns can be as high as 1,400 volts DC (or even higher). Typical semiconductor devices, including diodes or transistors, are typically unable to reliably operate under such high-voltage conditions. To address this, special diodes or transistors (referred to as power diodes or transistors) are utilized. Some shortcomings of such high-voltage semiconductor devices are their relatively high cost, low reliability, and relatively high leakage current, especially at high temperatures.